After Downey announced that he and his co-stars are "actually not done shooting," Ruffalo told THR that he had Dr. Bruce Banner's duds in his hotel room in anticipation of filming an unspecified scene.

At the end of a press conference Thursday in Los Angeles for the upcoming superhero movie The Avengers, Robert Downey Jr. revealed that despite the film having screened at the premiere Wednesday night, he and his co-stars still have a scene to shoot. “Not to keep you guessing, but we’re actually not done shooting,” Downey said. “We are shooting one more scene tonight. I’m not kidding.”

Downey’s reputation as a prankster led many to believe that he actually was kidding, especially after co-writer/director Joss Whedon later said that the actor was pulling everyone’s leg. But co-star Mark Ruffalo later backed Downey's claim to The Hollywood Reporter, saying that he, Downey and the rest of the cast actually were planning to film something Thursday night. Marvel had no comment when contacted for confirmation.

"Yeah, yeah -- we’re shooting a scene tonight,” Ruffalo said. “I don’t know where it’s going to go. I really don’t. We don’t even really know what it is yet, but we’re shooting a scene tonight.” Pointing to the closet of his hotel room, he said, “All I know is that my costume is in there, we’re putting on make-up, [and they’re saying] ‘show up here and we’re going to tell you what we’re going to do.’ ”

During a conversation later with THR, Whedon joked about the content of the scene and suggested again that Downey was only kidding. “We’re shooting another battle scene,” he said. “It’s probably a bad idea because we only have three hours.” When told that Ruffalo said his costume was on the premises, Whedon demurred: “Mark Ruffalo’s costume is made of CGI. Those guys are clowns.”

Ruffalo, of course, plays the Hulk, whose “costume” is a skintight suit that transforms the actor into the destructive green monster. But he clarified that he was going to be playing Dr. Bruce Banner in the scene. “No, no. I’m in my regular costume,” he said.

All of the Marvel movies since Iron Man have featured a post-credits coda or extra scene which either hints at the story for an upcoming film or expands the Marvel universe in general. When asked if the filmmakers might add an extra scene to the film between the premiere and The Avengers’ May 4 opening, Whedon said: “At this point, anything is possible. But I don’t want to do any more work. I’m so tired of this movie. No, I’m not! But I am so tired.”